title: Evoked response audiometry in scrub typhus: prospective, randomised, case-control study.
abstract: OBJECTIVE
  To investigate the hypothesis of cochlear and retrocochlear damage in scrub typhus, using evoked response audiometry.
  
  
  METHODS
  Prospective, randomised, case-control study.
  
  
  METHODS
  The study included 25 patients with scrub typhus and 25 controls with other febrile illnesses not known to cause hearing loss. Controls were age- and sex-matched. All subjects underwent pure tone audiometry and evoked response audiometry before commencing treatment.
  
  
  RESULTS
  Six patients presented with hearing loss, although a total of 23 patients had evidence of symmetrical high frequency loss on pure tone audiometry. Evoked response audiometry found significant prolongation of absolute latencies of wave I, III, V, and wave I-III interpeak latency. Two cases with normal hearing had increased interpeak latencies. These findings constitute level 3b evidence.
  
  
  CONCLUSIONS
  Findings were suggestive of retrocochlear pathology in two cases with normal hearing. In other patients, high frequency hearing loss may have led to altered evoked response results. Although scrub typhus appears to cause middle ear cochlear and retrocochlear damage, the presence of such damage could not be fully confirmed by evoked response audiometry.
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, Indira Gandhi Medical College, Shimla, 171001, HP, India. anujagdeep@yahoo.co.in
authors.forename: J S
authors.initials: JS
authors.lastname: Thakur
authors.forename: N K
authors.initials: NK
authors.lastname: Mohindroo
authors.forename: D R
authors.initials: DR
authors.lastname: Sharma
authors.forename: K
authors.initials: K
authors.lastname: Soni
authors.forename: S S
authors.initials: SS
authors.lastname: Kaushal
mesh_terms: D000293:Adolescent; D000328:Adult; D001300:Audiometry, Evoked Response / Q000379:methods*; D001301:Audiometry, Pure-Tone; D001309:Auditory Threshold / Q000502:physiology; D016022:Case-Control Studies; D002648:Child; D015834:Cochlear Diseases / Q000150:complications / Q000175:diagnosis / Q000503:physiopathology; D005260:Female; D006316:Hearing Loss, High-Frequency / Q000175:diagnosis / Q000209:etiology; D006319:Hearing Loss, Sensorineural / Q000175:diagnosis / Q000209:etiology; D006801:Humans; D008297:Male; D011446:Prospective Studies; D012181:Retrocochlear Diseases / Q000150:complications / Q000175:diagnosis* / Q000503:physiopathology; D012612:Scrub Typhus / Q000150:complications / Q000175:diagnosis* / Q000503:physiopathology; D055815:Young Adult